Neighbor polys and edges in Detour?

[S41L0R]

I'm working on something that requires neighbor edge and poly indices for each edge. I'm not really sure how to get this data. I was looking at dtPoly->neis, but I don't know how single-bit flags would help me. I also need to find neighbors in other tiles.
I really can't find that much documentation on dtPoly->neis, and so I don't really know if it's the thing for me.

Any advice?

[S41L0R]

Resolved!

Here's the solution I used for people looking at this in future:

• If the neighbor from dtPoly->neis & DT_EXT_LINK (0x8000), the link is external.
• If not, you can find the neighbor poly index by subtracting 1 from the neighbor. You can find the neighbor edge index by iterating through the neighbor poly and checking which edge shares vertices with the seeking edge.
• If it is external, you need to look at dtMeshTile->links. Documentation doesn't seem to be too great on that, so here's what I want to say about using that:
  • Each dtPoly has an index into dtMeshTile->links. This represents where the first link is, and you can iterate like this:
    for (unsigned int i = srcPoly->firstLink; i != DT_NULL_LINK; i = srcTile->links[i].next)
  • dtLink->ref corresponds to the linked poly, but don't let this fool you about dtLink->edge. That is the index of the edge within the poly you are iterating for. If you want to find the linked edge you will probably have to loop though the linked poly and looked for shared vertices.

Anyway, I hope that's helpful to anyone working on something similar in future!